Hi Jiawei,
I cannot speak for Ian, so it is just my view. Some of us - including me - have a special kind of humour and sometimes forget that not everything here is under the humor section. You are right telling us that do not share our kind of fun.

But do not take any of us too seriously.
Maybe if you extract the simple information, you can read some advice. Regardsless if it is what you want to read, think about it and make up your own decision, as no one here is God.

Well back to the track.
Personally, yes Aikido has given me a purpose for my life. Mostly in the sense that try to learn from the "Way of Harmonized Energies" - I know it is a bad translation, I just could't get it better right now - and apply it or some of it to the rest of my life. Aikido as practicing is great, but not a goal for me by itself.

And no Aikido is not everything, I want to do. I love my family and I love my job. So there are other things I want to do. And ven if i would have much more time, I would maybe some of them for windsurfing -can improve your balance, physically and mentally,too - or others. Well, somehow it is a "sex-and-drug-and-rock'n-roll" argument, if you want to point it out to extreme.

And again yes, being an uchi-deshi for 3 month, 6 month or a year would be great. At the moment it is not possible for me, and i do not know, if they would take a mid-40s either. I jut take it as a dream. If somehow everything is prepared, I might even have a try.

And my advice is also a warning. If you want to make aikido become everything in your life, the one and only purpose, you might look forward to a great life of harmony. But it is an unstable harmony. Any accident inside or outside the dojo can change your chances for ever. There are good examples that that need not stop your aikido practice in total, but probabilty does not show evidence that it will still can be the only thing you are doing then.

Do only aikido, become sensei, have your own dojo. What happens, if people do not want to pay enough for you to live? What if your students do not share your empathy and just want to come for fun? What if living together with other uch-deshi is not what you expected?

You may be disappointed and you should prepared. And you always should have a plan B.

Have a lot of fun. Maybe we meet sometimes on the mat.

Cordially Dirk